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Ross Donald
Joined: 15 Dec 2020
Posts: 16
Location: Bristol
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 Posted: Tue Dec 15, 2020 10:37 pm Post subject: Re: FINALLY |
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| McHale wrote: | | Ross Donald wrote: |
Gosh, you make it sound so simple!!!
I'm going to attempt the swop over tomorrow. I'll let you know how I got on.
Cheers!!!
Ross |
Be sure to replace the CR2032 battery on the replacement MoBo when you do. I forgot to and about a year later had to tear it down to replace it.
Good luck! |
Ah.... will do!!!
Thanks for reminding me.
Ross |
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Ross Donald
Joined: 15 Dec 2020
Posts: 16
Location: Bristol
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| Posted: Fri Dec 18, 2020 5:46 pm Post subject: Re: FINALLY |
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| Ross Donald wrote: | | McHale wrote: | | Ross Donald wrote: |
I've read your thread with great interest.
I too have a Korg Kronus (88 model), from 2012ish, and one day it just went dead, having been on and working......Had a look inside, and noticed the motherboard light is illuminated.
I managed to acquire an identical motherboard, and wondered if I just swop it over, and take care of the firmware update after it boots up? Or if I have to do anything else before the swop?
Any advice is gratefully received. |
Just a simple board swap. Once you get it in, perform all your updates as necessary and you'll be good to go. The MoBo I ordered from ebay had 4gb of RAM already on it and I installed it as well.
Good luck. Let us know how it goes.
-Mc |
Gosh, you make it sound so simple!!!
I'm going to attempt the swop over tomorrow. I'll let you know how I got on.
Cheers!!!
Ross |
********************
Sadly, the motherboard swop didn't bring my keyboard back to life.... looks like the power supply is goosed!! I knew it would be one or the other.... I had managed to acquire the motherboard, so that was first in line to be tried.... ah well.
I'm not sure how easy it will be to get hold of a power supply. I don't know where to start. |
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KK
Platinum Member
Joined: 13 Oct 2016
Posts: 1422
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| Posted: Fri Dec 18, 2020 7:45 pm Post subject: Re: FINALLY |
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| Ross Donald wrote: |
Sadly, the motherboard swop didn't bring my keyboard back to life.... looks like the power supply is goosed!! I knew it would be one or the other.... I had managed to acquire the motherboard, so that was first in line to be tried.... ah well.
I'm not sure how easy it will be to get hold of a power supply. I don't know where to start. |
Are you sure to have completed the mobo swap correctly ? Before concluding there is a PS problem, there are some things to check. You mentioned previously the mobo light was on before the swap. Is the new mobo light on as well ? Did you check the output voltages with a multimeter on the PS ? What happens when you start the unit ? Anything on the screen ? Does the fan start ? For sure remote diagnostic on a forum is not really efficient, but if you provide more info we might be able to find some clues. If there is a minimum of activity going on like at least the fan starting, connecting the Kronos mobo video out on a monitor will show you the Linux prompt, which can show errors and what happens at bootup. |
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Ross Donald
Joined: 15 Dec 2020
Posts: 16
Location: Bristol
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| Posted: Fri Dec 18, 2020 8:03 pm Post subject: Re: FINALLY |
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| KK wrote: | | Ross Donald wrote: |
Sadly, the motherboard swop didn't bring my keyboard back to life.... looks like the power supply is goosed!! I knew it would be one or the other.... I had managed to acquire the motherboard, so that was first in line to be tried.... ah well.
I'm not sure how easy it will be to get hold of a power supply. I don't know where to start. |
Are you sure to have completed the mobo swap correctly ? Before concluding there is a PS problem, there are some things to check. You mentioned previously the mobo light was on before the swap. Is the new mobo light on as well ? Did you check the output voltages with a multimeter on the PS ? What happens when you start the unit ? Anything on the screen ? Does the fan start ? For sure remote diagnostic on a forum is not really efficient, but if you provide more info we might be able to find some clues. If there is a minimum of activity going on like at least the fan starting, connecting the Kronos mobo video out on a monitor will show you the Linux prompt, which can show errors and what happens at bootup. |
Hi, and firstly thanks for your input. Much appreciated.
I was very methodical with the swop over, so I'm confident the install is ok. (inc RAM and new battery)
With the replacement motherboard, there is no life apart from the small mobo light, (which also appeared on the original motherboard). No fan life, no screen, and listening closely, curiously, no hum from power supply...... (although my 64 yr old ears have seen better days)
I've no means of connecting an external screen, and I'm not sure what I'm checking as regards the voltages on the various leads from the P/S.
I'm tending to towards pointing the finger at a faulty P/S.
Best Regards |
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KK
Platinum Member
Joined: 13 Oct 2016
Posts: 1422
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| Posted: Sat Dec 19, 2020 1:06 am Post subject: Re: FINALLY |
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| Ross Donald wrote: | Hi, and firstly thanks for your input. Much appreciated.
I was very methodical with the swop over, so I'm confident the install is ok. (inc RAM and new battery)
With the replacement motherboard, there is no life apart from the small mobo light, (which also appeared on the original motherboard). No fan life, no screen, and listening closely, curiously, no hum from power supply...... (although my 64 yr old ears have seen better days)
I've no means of connecting an external screen, and I'm not sure what I'm checking as regards the voltages on the various leads from the P/S.
I'm tending to towards pointing the finger at a faulty P/S.
Best Regards |
Hello Ross,
Thanks for bringing more details. I prepared for you below a little pic I took from inside my K2 during one of my numerous mods. 
Unfortunately, from what you mention, you could be right that the PS might be faulty. But if I were you, the next step I would do would be to check the voltages after turning the unit on (even if it doesn't show much running). Important : ONLY proceed if you feel totally at ease with taking measurements with a voltmeter/multimeter. The last thing you want is to electrocute yourself, so in doubt please DO NOT try and we might find other things to test. But I thought you are probably at ease with this since you just replaced the motherboard. 
So if you feel OK to go ahead, using a voltmeter/multimeter with rather pointy tip probes, turn the Kronos on, then place and keep the black/neg probe on the chassis or one of the PS screws. Set the meter to DC volts and then with the red/pos probe test what comes out of the connector pins as shown as on the pic. With narrow tip probes, it's easy to gently touch the metal surrounding each wire in their respective connector and get a measurement. You should read around what I wrote on the pic for the different colored wires. Black ones of course are ground wires so no need to test them. For safety, remember to stay away from the 120 VAC things, PS transfos and coiled things while you test. My apologies if I sound overprotective - maybe this is all easy for you, but I don't know about your technical abilities and I want you to be safe just in case. 
 |
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Ross Donald
Joined: 15 Dec 2020
Posts: 16
Location: Bristol
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| Posted: Sat Dec 19, 2020 9:16 am Post subject: Re: FINALLY |
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| KK wrote: | | Ross Donald wrote: | Hi, and firstly thanks for your input. Much appreciated.
I was very methodical with the swop over, so I'm confident the install is ok. (inc RAM and new battery)
With the replacement motherboard, there is no life apart from the small mobo light, (which also appeared on the original motherboard). No fan life, no screen, and listening closely, curiously, no hum from power supply...... (although my 64 yr old ears have seen better days)
I've no means of connecting an external screen, and I'm not sure what I'm checking as regards the voltages on the various leads from the P/S.
I'm tending to towards pointing the finger at a faulty P/S.
Best Regards |
Hello Ross,
Thanks for bringing more details. I prepared for you below a little pic I took from inside my K2 during one of my numerous mods.
Unfortunately, from what you mention, you could be right that the PS might be faulty. But if I were you, the next step I would do would be to check the voltages after turning the unit on (even if it doesn't show much running). Important : ONLY proceed if you feel totally at ease with taking measurements with a voltmeter/multimeter. The last thing you want is to electrocute yourself, so in doubt please DO NOT try and we might find other things to test. But I thought you are probably at ease with this since you just replaced the motherboard.
So if you feel OK to go ahead, using a voltmeter/multimeter with rather pointy tip probes, turn the Kronos on, then place and keep the black/neg probe on the chassis or one of the PS screws. Set the meter to DC volts and then with the red/pos probe test what comes out of the connector pins as shown as on the pic. With narrow tip probes, it's easy to gently touch the metal surrounding each wire in their respective connector and get a measurement. You should read around what I wrote on the pic for the different colored wires. Black ones of course are ground wires so no need to test them. For safety, remember to stay away from the 120 VAC things, PS transfos and coiled things while you test. My apologies if I sound overprotective - maybe this is all easy for you, but I don't know about your technical abilities and I want you to be safe just in case.
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Hi KK
Thanks agin for all your help.
I'm not trained as a technician, but always willing to give it a go.......
I got down to work this morning and did a check on the voltages as you explained, and other than one or two brief tiny flickers of .001 on the 20 volt scale, there's nothing reading from any of the pins on that loom. I pulled out the loom to get direct contact with the pins on the P/S board too, just in case my probe was not 'pointy' enough, but the same results.
I also checked the P/S is receiving 230 volts AC.
So, with these findings, it looks like the P/S has failed.....
Do you know if these P/Ss are available? |
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KK
Platinum Member
Joined: 13 Oct 2016
Posts: 1422
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| Posted: Sat Dec 19, 2020 1:37 pm Post subject: Re: FINALLY |
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| Ross Donald wrote: |
Hi KK
Thanks agin for all your help.
I'm not trained as a technician, but always willing to give it a go.......
I got down to work this morning and did a check on the voltages as you explained, and other than one or two brief tiny flickers of .001 on the 20 volt scale, there's nothing reading from any of the pins on that loom. I pulled out the loom to get direct contact with the pins on the P/S board too, just in case my probe was not 'pointy' enough, but the same results.
I also checked the P/S is receiving 230 volts AC.
So, with these findings, it looks like the P/S has failed.....
Do you know if these P/Ss are available? |
Hello Ross,
If you are sure the meter was set on the VDC scale (not VAC), then it would confirm the PS is defective. Sorry about that. About where to find a replacement one, I have no idea but I suppose I would first contact Korg service by email to see what they say (try support@korgusa.com even if you are in the UK, they usually reply rather quickly, even though right now it's Holidays time. You can of course as well try a local Korg service center).
The model is ENO-1612 made by Enhance USA. Maybe you could contact them as well.
http://www.enhanceusa.com/webe/html/products/show.aspx?num=90&kw=eno-1612&page=1
Also their contact page :
http://www.enhanceusa.com/webe/html/contact/index.aspx |
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Ross Donald
Joined: 15 Dec 2020
Posts: 16
Location: Bristol
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| Posted: Sat Dec 19, 2020 2:08 pm Post subject: Re: FINALLY |
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| KK wrote: | | Ross Donald wrote: |
Hi KK
Thanks agin for all your help.
I'm not trained as a technician, but always willing to give it a go.......
I got down to work this morning and did a check on the voltages as you explained, and other than one or two brief tiny flickers of .001 on the 20 volt scale, there's nothing reading from any of the pins on that loom. I pulled out the loom to get direct contact with the pins on the P/S board too, just in case my probe was not 'pointy' enough, but the same results.
I also checked the P/S is receiving 230 volts AC.
So, with these findings, it looks like the P/S has failed.....
Do you know if these P/Ss are available? |
Hello Ross,
If you are sure the meter was set on the VDC scale (not VAC), then it would confirm the PS is defective. Sorry about that. About where to find a replacement one, I have no idea but I suppose I would first contact Korg service by email to see what they say (try support@korgusa.com even if you are in the UK, they usually reply rather quickly, even though right now it's Holidays time. You can of course as well try a local Korg service center).
The model is ENO-1612 made by Enhance USA. Maybe you could contact them as well.
http://www.enhanceusa.com/webe/html/products/show.aspx?num=90&kw=eno-1612&page=1
Also their contact page :
http://www.enhanceusa.com/webe/html/contact/index.aspx |
Hi KK
Yes I made sure it was VDC and not VAC, but you're right to ask!!! So, am I right in assuming that it's the 'primary' circuit of the P/S that is likely faulty, if all the various outputs are showing nothing?
Thanks so much for the possible P/S supplier links..... you have been so much help.
Have a wonderful Christmas.
Ross |
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KK
Platinum Member
Joined: 13 Oct 2016
Posts: 1422
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| Posted: Sat Dec 19, 2020 7:29 pm Post subject: Re: FINALLY |
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| Ross Donald wrote: |
Hi KK
Yes I made sure it was VDC and not VAC, but you're right to ask!!! So, am I right in assuming that it's the 'primary' circuit of the P/S that is likely faulty, if all the various outputs are showing nothing? |
Hi Ross,
Indeed it looks like something is open. Could be simple as an open diode. I never took the time to analyze the Kronos PS in detail, but usually there is a fuse somewhere. I'm wondering if that strange covered black thing installed perpendicular to the 120VAC/230VAC connector (with yellow and black wires) is a special type fuse (there are many variants of fuses - I saw quite strange looking ones on certain specialized PCBs before). in other words, if you look on my pic above, in the lower right just above two blue components and in between the AC connector and a green relay, you see that strange black thing. Try to see if you can read anything on it, a model number, etc. From there, we could make sure it's a fuse (or not) and then if it's indeed the case it would be a thing to test later using an ohmmeter with the PS totally unplugged from the Kronos. I tell you this because I read this writing about fuse rating on the PCB close to the green relay at the bottom of the pic.
Of course, it could also be something else like an open winding on one of the relays, on one of the transfos, open diode(s), etc. Do you notice any component which looks burnt or any burnt smell when you start the Kronos ? Meanwhile, for sure try to contact the links above and hopefully they can send you a new PS quickly.
Please have a great Christmas too and stay safe.  |
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Ross Donald
Joined: 15 Dec 2020
Posts: 16
Location: Bristol
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| Posted: Sat Dec 19, 2020 7:52 pm Post subject: Re: FINALLY |
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| KK wrote: | | Ross Donald wrote: |
Hi KK
Yes I made sure it was VDC and not VAC, but you're right to ask!!! So, am I right in assuming that it's the 'primary' circuit of the P/S that is likely faulty, if all the various outputs are showing nothing? |
Hi Ross,
Indeed it looks like something is open. Could be simple as an open diode. I never took the time to analyze the Kronos PS in detail, but usually there is a fuse somewhere. I'm wondering if that strange covered black thing installed perpendicular to the 120VAC/230VAC connector (with yellow and black wires) is a special type fuse (there are many variants of fuses - I saw quite strange looking ones on certain specialized PCBs before). in other words, if you look on my pic above, in the lower right just above two blue components and in between the AC connector and a green relay, you see that strange black thing. Try to see if you can read anything on it, a model number, etc. From there, we could make sure it's a fuse (or not) and then if it's indeed the case it would be a thing to test later using an ohmmeter with the PS totally unplugged from the Kronos. I tell you this because I read this writing about fuse rating on the PCB close to the green relay at the bottom of the pic.
Of course, it could also be something else like an open winding on one of the relays, on one of the transfos, open diode(s), etc. Do you notice any component which looks burnt or any burnt smell when you start the Kronos ? Meanwhile, for sure try to contact the links above and hopefully they can send you a new PS quickly.
Please have a great Christmas too and stay safe. |
KK
Great, I'll have a look at that.......
Looks like our Xmas is shelved this year with the latest lockdown....... nearly a year on with umpteen lockdowns, and we're worse off now.... ah well. |
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KK
Platinum Member
Joined: 13 Oct 2016
Posts: 1422
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| Posted: Sat Dec 19, 2020 8:07 pm Post subject: Re: FINALLY |
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| Ross Donald wrote: |
KK
Great, I'll have a look at that.......
Looks like our Xmas is shelved this year with the latest lockdown....... nearly a year on with umpteen lockdowns, and we're worse off now.... ah well. |
Hi Ross,
Yep, here too Holidays visits will be very restricted. About the PS, that would be one of the first components I would check because of the fuse rating mention nearby the green relay and also as it seems to be the first thing connecting the AC plug to the rest of the PCB (too bad we can't see under the PS and follow the trace of the AC yellow wire on the PCB). Try to see any number written on the sides of that black component. In any case, stay safe and disconnect the Kronos before any checkup. |
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AntonySharmman
Approved Merchant
Joined: 16 Oct 2010
Posts: 3595
Location: Hellas
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| Posted: Sat Dec 19, 2020 11:06 pm Post subject: |
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Ross
This SMPS PSU do not work if disconnected from mobo and just plug 100-300V input , as any motherboard PSU since it has an enable
pin that must be grounded , therefore you will measure zero output voltages this way !
I had written at that time in earlier post :
In order to test Enhance ENO-1612 (outside Kronos) , plug in 90-300 Volts AC (or DC) input , ground green cable (PS-on)
and then check all voltage outputs as described in bellow technical sheet , page 2.
http://www.enhanceusa.com/upload/DM/201310030839530.pdf (link no longer available)
_________________
Music Conductor - Sound Engineer & Developer - Automotive SMPS/RF R&D - Electronics Engineer
PaSeries Demos - WavesArt.eu - KorgPa.gr <> Facebook
Keyboards : Steinway-D, Kronos X, Pa5X 76, Pa4X 76, Montage M7 , Roland-XV88, Emu3,Emax II,Synclavier II,Yamaha DX Series, ΟΒ-8V |
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Ross Donald
Joined: 15 Dec 2020
Posts: 16
Location: Bristol
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| Posted: Sun Dec 20, 2020 9:59 pm Post subject: Re: FINALLY |
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| Ross Donald wrote: | | KK wrote: | | Ross Donald wrote: |
Hi KK
Thanks agin for all your help.
I'm not trained as a technician, but always willing to give it a go.......
I got down to work this morning and did a check on the voltages as you explained, and other than one or two brief tiny flickers of .001 on the 20 volt scale, there's nothing reading from any of the pins on that loom. I pulled out the loom to get direct contact with the pins on the P/S board too, just in case my probe was not 'pointy' enough, but the same results.
I also checked the P/S is receiving 230 volts AC.
So, with these findings, it looks like the P/S has failed.....
Do you know if these P/Ss are available? |
Hello Ross,
If you are sure the meter was set on the VDC scale (not VAC), then it would confirm the PS is defective. Sorry about that. About where to find a replacement one, I have no idea but I suppose I would first contact Korg service by email to see what they say (try support@korgusa.com even if you are in the UK, they usually reply rather quickly, even though right now it's Holidays time. You can of course as well try a local Korg service center).
The model is ENO-1612 made by Enhance USA. Maybe you could contact them as well.
http://www.enhanceusa.com/webe/html/products/show.aspx?num=90&kw=eno-1612&page=1
Also their contact page :
http://www.enhanceusa.com/webe/html/contact/index.aspx |
Hi KK
Yes I made sure it was VDC and not VAC, but you're right to ask!!! So, am I right in assuming that it's the 'primary' circuit of the P/S that is likely faulty, if all the various outputs are showing nothing?
Thanks so much for the possible P/S supplier links..... you have been so much help.
Have a wonderful Christmas.
Ross |
Had another thought..... the spare MB I acquired had 1GB RAM module fitted. Am I able to add this RAM to my Kronus MB which still has one slot free? It's fitted with a 2GB RAM module already. So that would be 3GB in total, but mixed values........ they are both DDR2 modules. Would I notice a difference with this fitted? |
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entonio
Joined: 19 Sep 2020
Posts: 37
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| Posted: Mon Dec 21, 2020 3:02 am Post subject: |
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| Is the title of this now incredibly long thread appropriate? Does the OS update have anything to do with the problem? |
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KK
Platinum Member
Joined: 13 Oct 2016
Posts: 1422
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| Posted: Mon Dec 21, 2020 4:08 am Post subject: Re: FINALLY |
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| Ross Donald wrote: | | Had another thought..... the spare MB I acquired had 1GB RAM module fitted. Am I able to add this RAM to my Kronus MB which still has one slot free? It's fitted with a 2GB RAM module already. So that would be 3GB in total, but mixed values........ they are both DDR2 modules. Would I notice a difference with this fitted? |
Hi Ross,
You can add up to 4 GB of RAM on a Kronos, so that would increase the available memory. My K2 came stock with just one 4 GB RAM stick inserted. I suggest you don't install it right away though - wait until your unit is running again first. |
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